'IntendedFor' field needs to point to an existing file

Hi,
I have the same error with my phantom data and it seems I have already included the session and there is no problem with the file name. But still I have the error. Could you please help? This is the link to my question/discussion, but here is the problem:

I have inserted the IntendedFor field to my AP and PA b0 images of the DWI data in the corresponding JSON files that point to the DWI data. The DWI image is present, but still, the bids-validator complains and gives the following error:
Location
UC042121QA/sub-QA042121/ses-phantom/fmap/sub-QA042121_ses-phantom_acq-dwib0_dir-AP_epi.nii.gz

Reason
'IntendedFor' property of this fieldmap ('/sub-QA042121/ses-phantom/fmap/sub-QA042121_ses-phantom_acq-dwib0_dir-AP_epi.nii.gz') does not point to an existing file('ses-phantom/dwi/sub-QA042121_ses-phantom_dwi.nii.gz'). Please mind that this value should not include subject level directory ('/sub-QA042121/').

Evidence
ses-phantom/dwi/sub-QA042121_ses-phantom_dwi.nii.gz

This is how I have inserted the IntendedFor field:
"IntendedFor": ["ses-phantom/dwi/sub-QA042121_ses-phantom_dwi.nii.gz"],

Even if I pass the path to DWI data as a string and not as a list, I still get the same error. I also have the correct permissions in my parent directory. Is there any issue with any keyword in the subject/session name maybe e.g. phantom?

Please help!
Thanks.